For many, starting an ED medication means increasing or returning to sexual activity. With that comes the positive aspects of sexual intimacy. However, it also comes with potentially uncomfortable conversations about sexually transmitted infections. Sharing your STI status is an important part of allowing your partner to make a truly informed decision about having sex.

If you have a sexually transmitted infection, you must inform any potential sexual partner. Moreover, this should be done before engaging in any activity that risks giving them an infection. It is also important to ask any prospective partner about their status. Lastly, while condoms are helpful in reducing the risk of pregnancy, transmitting, or acquiring an infection, they can never be 100% effective. That is why informed consent is such an important part of sharing sexual intimacy with honesty and clarity.

There are hundreds of medications that can interact with Cialis. Most are not severe but some can be life threatening, as with any nitrates, nitrites, or nitroglycerin. Even simple over the counter medications should be checked for interactions. Remember, something as safe as grapefruit can alter how your body handles a phosphodiesterase inhibitor (Viagra, Sildenafil, Cialis, Levitra). All your providers should be kept informed of any medication that is added, dropped, or changed in your regimen.

The Physician Desk Reference (PDR) lists the medications that can interact with Cialis, along with the contraindications to its use. The PDR is included because it is comprehensive and must be read in its entirety. Contraindications can be absolute, as with nitrates/nitrites, act as relative warnings about drug interactions, and inform patients and healthcare providers how certain conditions can affect the metabolism of Cialis, either increasing or decreasing the amount in the blood. A few relevant sections are summarized below concerning contraindications and drug interactions, but it is not a complete overview. Please, read the entire package insert, as well.

General information:

It should not be used in anyone allergic to any of the components used to make Cialis tablets. Also, as discussed above, some patients are on multiple phosphodiesterase inhibitors at the same time, but this is not recommended. It has not been studied. In patients with PVOD, which is pulmonary veno-occlusive disease, significant worsening of their cardiovascular system (heart and blood vessel status) may occur. Also, Cialis is not recommended when a patient is on alpha blockers when they are given for an enlarged prostate. As can be seen in the drug interaction section below, caution must be exercised when Cialis is combined with alpha blockers being used for any reason. Used together they can lower blood pressure too greatly.

Nitrate/Nitrite Therapy

ABSOLUTELY no one should take Cialis if they “are currently on nitrate/nitrite therapy.” That includes even if the patient uses of nitrates/nitrite therapy intermittently. Also, no one who uses recreational nitrates/nitrites (poppers, etc.) should use Cialis.

Geriatric (The Elderly), Hepatic (Liver) Disease, Renal (Kidney) Impairment

Cialis is metabolized by a complex system that can be compromised in the elderly, or in patients who suffer from liver disease, or those whose kidney function is reduced by illness or age. It is generally very well tolerated in the elderly but the dose given should be adjusted if the patient has mild to moderate liver impairment, whether due to age or illness. The same is true for those whose kidney is compromised for any reason. Also, it is not recommended for use in patients with severe liver impairment, and daily use is not recommended at any dose for patients “when the creatinine clearance is less than 30 ml/minute (which means the kidney is severely compromised) or the patient has renal failure or is receiving dialysis.”

Moreover, certain drugs have a dramatic effect on the metabolism of Cialis similarly increasing the blood level dramatically. Therefore, those taking erythromycin, itraconazole, ketoconazole, saquinavir, and ritonavir should have very significant dosage adjustments made.

Angina (Chest Pain), Cardiac Arrhythmias (Irregular Heartbeats), Cardiac Disease (Heart Disease), Coronary Artery Disease (Narrowing of the Heart Arteries), Heart Failure, Hypertension (High Blood Pressure), Hypotension (Low Blood Pressure), IHSS (Idiopathic Hypertrophic Subaortic Stenosis–a Heart Defect), Hypovolemia (Low Blood Volume–like dehydration), Myocardial Infarction (Heart Attack), Stroke (like a heart attack but affecting the brain)

“There is a degree of cardiac risk associated with sexual activity; therefore, prescribers, should evaluate the cardiovascular status of their patients prior to initiating any treatment for erectile dysfunction.” [NOTE: This means that if you and your provider have a reason to believe after diagnosing erectile dysfunction that you are not healthy enough for sex, you shouldn’t use anything that will help you have sex until you are healthier. Your doctor and nurse practitioner count on an honest answer about your health and your capacity to be sexually active. It may seem overly cautious but think about it; if you aren’t healthy enough for sex, shouldn’t you take care of your health before trying to regain your sex life? There have been over 75 heart attacks associated with the use of another phosphodiesterase inhibitor. It may not seem like many deaths but you don’t want to be the person who bumps that number over 100.]

The PDR states, “the manufacturer does not recommend the use of tadalafil be used in these groups until more data are available: myocardial infarction (heart attack) in the last 90 days, coronary artery disease resulting in unstable angina (chest pain) or angina occurring during sexual intercourse, NYHA Class II or greater heart failure in the last six months, uncontrolled cardiac arrhythmias (irregular heart beats), hypotension (BP<90/50), uncontrolled hypertension (BP>170/100), or a stroke in the last 6 months.”

The PDR also notes that the American College of Cardiology recommends that Cialis be used in caution with patients (not on nitrates, of course) with active coronary ischemia, meaning they have blocked heart arteries that is compromising the function of their heart, such as would show by having symptoms like chest pain or by failing a stress test. They also advise caution in anyone with low blood pressure or low blood volume or in anyone with high blood pressure on a “complicated, multidrug, antihypertensive program.” Patients with “Left Ventricular Outflow Obstruction (e.g., aortic stenosis, idiopathic hypertrophic subaortic stenosis)” should be approached with caution as they, and patients with poor control of the swings in their blood pressure, can be very sensitive to Cialis and other vasodilators (drugs that open up the blood vessels). They also point out that it should be used with caution if the patient is on other drugs that can markedly elevate the level of Cialis in the blood.

Leukemia, Multiple Myeloma, Penile Structural Abnormality, Polycythemia, Priapism, Sickle Cell Disease

Priapism is an erection lasting more than 4 hours and it can occur with the use of tadalafil. Priapism can be painful but, with or without pain, an erection that lasts over 4 hours could result in damage to the tissues of the penis. People with the above conditions are at greater risk of suffering from priapism with the use of Cialis (tadalafil). The PDR states, “Use tadalafil, and other agents for the treatment of erectile dysfunction, with caution in patients with penile structural abnormality (such as angulation, cavernosal fibrosis, or Peyronie’s disease), or in patients who have conditions which may predispose them to priapism (such as sickle cell disease, leukemia, multiple myeloma, polycythemia, or history of priapism).”

Human Immunodeficiency Virus (HIV) Infection

The PDR states, “tadalafil, when used for erectile dysfunction, offers no protection against sexually transmitted disease.”

Gastroesophageal Reflux Disease (GERD–heartburn due to reflux of acid), Hiatal Hernia (part of stomach slips upward through the diaphragm), Peptic Ulcer Disease (Stomach Ulcer)

The phosphodiesterase inhibitors decrease the pressure of the valve that stops acid from coming back up from the stomach and into the esophagus. It also inhibits the movement of the esophagus itself. It could make symptoms worse for people with GERD or a hiatal hernia so it is recommended that it be used with caution in these patients. Also, since it has yet to be studied, caution is recommended in patients with active peptic ulcer disease (bleeding stomach ulcers).

Non-arteritic Anterior Ischemic Optic Neuropathy (NAION), Retinitis Pigmentosa, Visual Disturbance

The PDR states, “Use tadalafil cautiously in patients with pre-existing visual disturbance. Postmarketing reports of sudden vision loss have occurred with phosphodiesterase inhibitors. Vision loss is attributed to a condition known as non-arteritic anterior ischemic optic neuropathy (NAION), where blood flow is blocked to the optic nerve.” It is never recommended for patients with known hereditary degenerative retinal disorders, including retinitis pigmentosa.

A Special Warning for Pilots and Air Traffic Controllers

Some people experience visual side effects when taking PDE5 inhibitors for erectile dysfunction. Due to the sensitive nature of their work, pilots and air traffic controllers should not take Viagra or sildenafil within 6 hours of aviation related duties. Cialis (tadalafil) is a much longer acting medication. Pilots and air traffic controllers should not take Cialis within 36 hours of aviation related duties. Daily Cialis use, at any dose, is not an option for men with these professions.

Hematological Disease

Phosphodiesterase type 5 is found in platelets (the cells that help us clot and stop bleeding when it occurs). Therefore caution is recommended if tadalafil is given to patients with bleeding disorders. There are other situations that would give a healthcare provider pause. Some would be if you have lightheadedness, fainting spells, leg cramping when you walk, inability to climb stairs or walk a few blocks without getting short of breath, or if you have allergies to any of the other phosphodiesterases or their components. These, and any other symptoms, must be discussed.

The list below is long and not one drug on the list is meaningless. That is why we need to know every drug you take and every healthcare provider needs to know you take Cialis.

Note: Some medications are not on the list but are included in the PDR, which is why it must be read as well. In addition, the list changes as medications may be added over time.

• Alpha-blockers (e.g., Cardura, Coreg Flomax, Hytrin, Minipress, Oravase, Rapaflo, Regitine,Trandate) (Treats High Blood Pressure or Enlarged Prostate)

• Ambrisentan (Letairis) (Treats PAH–High Blood Pressure in the Arteries of the Lungs)

• Amiodarone (Cordarone IV) (An IV drug used to treat serious irregular heartbeats)

• Amprenavir (Agenerase) (Treats HIV)

• Amyl Nitrite (Amyl nitrite Systemic, Poppers, Rush) (Recreational Drug)

• Aprepitant (Emend) (Treats Nausea)

• Atazanavir (Reyataz) (Treats HIV)

• Boceprevir (Pegasys, Pegintron) (Treats PAH and Hepatitis C)

• Butyl Nitrate (Poppers, Rush, Liquid Gold) (It is a recreational drug)

• Brigatinib (Alunbrig) (Cancer)

• Cariprazine (Vraylar) (Psychiatric Disorders)

• Ceritinib (Zykadia) (Cancer)

• Cimetidine (Tagamet) (Stomach Ulcers)

• Clarithromycin (Biaxin) (Antibiotic)

• Clopidogrel (Plavix) (Blood Thinner)

• Cobicistat (Stribild, Tybost) (Treats HIV)

• Conivaptan (Vaprisol) (Treats Low Sodium in the blood)

• Crizotinib (Xalkori) (Cancer)

• Darunavir (Prezista) (Treats HIV)

• Dasabuvir (Viekira XR, Viekira Pak–contains Ritonavir*) (Treats Hepatitis C)

• Delavirdine (Treats HIV)

• Dihydroergotamine (Migranal) (Treats Migraines)

• Diltiazem (e.g., Cartia, Cardizem, Dilacor XR, Tiazac,) (Treats High Blood Pressure)

• Doxazosin (Cardura, Carduran) (Treats High Blood Pressure or Enlarged Prostate)

• Dronedarone (Multaq) (Irregular Heartbeats)

• Duloxetine (Cymbalta) (Treats Depression and certain nerve pain disorders)

• Elbasvir; Grazoprevir (Zepatier) (Treats Hepatitis C)

• Erythromycin (Erythrocin, Ery-Tab, E-Mycin, Eryc) (Antibiotic)

• Fluconazole (Diflucan) (Treats Fungal and Yeast Infections)

• Fluoxetine (e.g., Prozac, Sarafem) (Treats Psychiatric disorders like depression)

• Fluvoxamine (Faverin, Fevarin, Floxyfral, Dumyrox, Luvox) (Treats OCD)

• Fosamprenavir (Lexiva) (Treats HIV)

• Grapefruit juice

• Hydralazine; Isosorbide dinitrate, ISDN (e.g., Bidil) (Heart Failure)

• Idelalisib (Zydelig) (Treats Cancer–Leukemia)

• Imatinib (Gleevec) (Treats Cancer–Leukemia)

• Indinavir (Crixivan) (Treats HIV)

• Isavuconazonium (Cresemba) (Treats Fungal Infections)

• Isoniazid. INH (Nydrazid) (Treats Tuberculosis TB)

• Isosorbide Dinitrate or Monohydrate (Isordil Titradose, Dilatrate-SR, Imdur, Imdur ER, Ismo, Monoket, IsoDitrate) (Treats Heart Disease and Chest Pain)

• Itraconazole (Sporanox, Onmel) (Treats Fungus and Yeast)

• Ivacaftor (Kalydeco) (Treats Cystic Fibrosis)

• Ketoconazole (Nizoral, Extina, Ketodan Kit, Kuric, Nizoral A-D, Xolegel) (Treats Fungal Infections)

• Lopinavir; Ritonavir (Kaletra) (Contains Ritonavir and Treats HIV)

• Lorcaserin (Belviq) (Weight Control)

• Lurasidone (Latuda) (Treats Depression)

• Mifepristone, RU-486 (Korlym, Mifeprex) (Treats Cushing’s Syndrome and Ends Pregnancy)

• Mitotane (Lysodren) (Treats Cancer and Cushing’s Syndrome)

• Monoamine oxidase inhibitors (e.g., Azilect, Marplan, Nardil, Parnate) (Treats Depression)

• Nefazodone (Serzone) (Treats Depression)

• Nelfinavir (Viracept) (Treats HIV)

• Netupitant (Akynzeo) (Prevents Nausea and Vomiting)

• Nifedipine (Procardia, Nifedical XL, Adalat, Procardia XL) (Heart Disease among others)

• Nilotinib (Tasigna) (Treats Cancer–Leukemia)

• Nitrates (Isordil Titradose, Dilatrate-SR, Imdur, Imdur ER, Ismo, Monoket, IsoDitrate) (Treats Heart Disease and Chest Pain)

• Nitroglycerin (Nitro-bid, Nitrocot SA Capsule, Nitro-dur, Nitrostat, Nitrodisc, Nitrek transdermal, Minitran, Nitrol ointment, Transderm-Nitro, Nitro-Time, Nitrotab, NitroMist, Nitro-Par, Nitrolingual, Nitroquick, Transderm-Nitro, Nitrogard, Nitroglyn, Nitrong) (Treats Chest Pain and Heart Conditions)

• Nitroprusside (Nipride RTU, Nitropress) (Heart Failure and High Blood Pressure)

• Ombitasvir; Paritaprevir; Ritonavir (Technivie, Viekira Pak) (Treat Hepatitis C)

• Pazopanib (Votrient) (Treats Kidney Cancer)

• Phenoxybenzamine (Dibenzyline) (Treat High Blood Pressure and Pheochromocytoma)

• Phentolamine (Regitine, Oraverse) (Erectile Dysfunction, High Blood Pressure)

• Phenylephrine (e.g.,Sudafed) (Decongestant)

• Posaconazole (Noxafil) (Treats Fungal Infections)

• Prazosin (e.g., Minipress, Vasoflex, Lentopres, Hypovase) (Treats High Blood Pressure, PTSD, and Anxiety)

• Quinidine (Cardioquin, Quinaglute, Quinalan, Quinidex Extentabs) (Treats Malaria and abnormal heart beats)

• Ranolazine (Ranexa) (Treats Chest Pain)

• Ribociclib (Kisqali) (Treats Cancer)

• Riociguat (Adempas) (Treats High Blood Pressure in the Arteries of the Lung)

• Ritonavir (Norvir) (Also found in Technivie and Viekira Pak) (Treats HIV and Hepatitis C)

• Sapropterin (Kuvan) (Treats a disorder that causes amino acid buildup in the brain)

• Saquinavir (Invirase, Fortovase) (Treats HIV)

• Silodosin (Rapaflo) (Treats an Enlarged Prostate)

• Tamsulosin (Flomax) (Treats an Enlarged Prostate)

• Telaprevir (Incivek, Incivo) (Treats Hepatitis C)

• Telithromycin (Ketek, Ketek Pak) (Antibiotic)

• Telotristat Ethyl (Xermelo) (Treats diarrhea in cancer patients)

• Terazosin (Hytrin) (Treats High Blood Pressure)

• Tipranavir (Aptivus) (Treats HIV)

• Verapamil (Calan, Isoptin) (Treats High Blood Pressure, Angina, Irregular Heart Beats)

• Vigabatrin (Sabril) (Treats Seizure Disorders)

• Voriconazole (Vfend) (Treats Fungal Infections)

Again, to one degree or another, all the phosphodiesterase inhibitors have common or not unusual side effects They can cause headaches (10%-16%), nasal stuffiness (1%-10%), flushing (5%-12%), dizziness (~3%), and upset stomach (4%-12%). [Drugs 2005;65:1621-1650] Some can cause blue tinted vision as a side effect.The medicine prescribed is safe but some rare side effects can occur, as well. Please take a few minutes to familiarize yourself with the list of both common and rare side effects provided here.

Important: If any unusual side effect happens, contact us; however, if there is anything severe or emergent go immediately to an emergency room. Any new symptom is worth pursuing. Any severe symptom must be pursued as an emergency. Symptoms such as chest pain, shortness of breath, severe headache, fainting, visual changes, or anything out of the ordinary, even lightheadedness, warrant a visit to the ER. Contact us after it is addressed. Again, take the time to read the list of potential side effects. It doesn’t matter how rare a side effect is if you are experiencing it.